Lost Chocolate Lab: Missing Male, 9mos, Black Collar

Male, 9months old Chocolate Labrador. He was wearing a black collar with white stitching. At 10pm approx, I opened the driveway gates to let a friend drive in. I let him go out to sit on the grass next door to chew his ball. I went back inside and returned 10-15mins later. We roamed the streets driving and calling out for an hour + but no sight of him.